A brazen bandit, posing as a postal worker, knocked off two Capital One banks within 10 minutes in Queens yesterday, authorities said.

The robber — clad in the warm-weather postal uniform of dark-blue shorts and a light-blue shirt — entered the Capital One branch on 164th Street in Kew Gardens at 9 a.m. He demanded cash while flashing a handgun in his waistband, cops said. The crook, who turned up 10 minutes later at another branch on Main Street in Flushing, came away with a total of around $3,000, sources said.